In manufacturing integrated circuits, various thin films are deposited and patterned on a semiconductor substrate. One deposition process is continuous chemical vapor deposition (CVD). In a continuous CVD process, a gaseous precursor is delivered to a reaction chamber to contact a heated substrate, e.g., a semiconductor workpiece. The precursor then dissociates in a chemical reaction to coat the substrate with a layer of deposited material. Another deposition process is pulsed CVD, which includes delivering one or more gas precursors in pulses. Atomic layer deposition (ALD) is one pulsed CVD process. In an ALD process, a layer of first chemical forms on a substrate surface and self limits to a monolayer. The first chemical is then purged from the system. A second chemical is then introduced to react with the first chemical and is then purged from the system. This process can be repeated until a layer of the desired thickness is deposited onto the substrate.
In both continuous CVD and ALD processes, the precursor must be delivered in a gaseous state. Many potentially useful precursors have relatively high vaporization temperatures, and these precursors must be heated in a vaporizer before being delivered to the reaction chamber. However, such heating can adversely affect certain precursors. For example, some precursors can decompose at elevated temperatures and contaminate and/or clog the vaporizer and/or other components of a deposition system. The deposition system typically must be shut down for clogged or contaminated lines, which can reduce product throughput and increase manufacturing cost. Therefore, there is a need for efficiently and cost-effectively maintain the vaporizer.